CESAM and Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
FEMS Microbiol Ecol. 2010 Sep;73(3):486-99. doi: 10.1111/j.1574-6941.2010.00913.x. Epub 2010 May 25.
As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutrition, whereas isotopic signatures of B. mauritanicus suggest methanotrophic nutrition. The indication by stable isotope analysis that chemosynthetic bacteria make a substantial contribution to the nutrition of the bivalves led us to investigate their associated bacteria and their phylogenetic relationships based on comparative 16S rRNA gene sequence analysis. PCR-denaturing gradient gel electrophoresis analysis and cloning of bacterial 16S rRNA-encoding genes confirmed the presence of sulfide-oxidizing symbionts within gill tissues of many of the studied specimens. Phylogenetic analysis of bacterial 16S rRNA gene sequences demonstrated that most bacteria were related to known sulfide-oxidizing endosymbionts found in other deep-sea chemosynthetic environments, with the co-occurrence of methane-oxidizing symbionts in Bathymodiolus specimens. This study confirms the presence of several chemosynthetic bivalves in the Gulf of Cadiz and further highlights the importance of sulfide- and methane-oxidizing symbionts in the trophic ecology of macrobenthic communities in MV.
在其他冷渗流中，来自加的斯湾泥火山的优势双壳类动物是属于 Solemyidae（Acharax sp.，Petrasma sp.）、Lucinidae（Lucinoma sp.）、Thyasiridae（Thyasira vulcolutre）和 Mytilidae（Bathymodiolus mauritanicus）科的大型动物。在 Solemyid、Lucinid 和 Thyasirid 标本中测量的 δ13C 值支持硫营养假说，而 B. mauritanicus 的同位素特征表明其为甲烷营养。稳定同位素分析表明，化能合成细菌对双壳类动物的营养有很大的贡献，这促使我们根据比较 16S rRNA 基因序列分析来研究它们的相关细菌及其系统发育关系。PCR-变性梯度凝胶电泳分析和细菌 16S rRNA 编码基因的克隆证实了许多研究标本的鳃组织中存在硫化物氧化共生体。细菌 16S rRNA 基因序列的系统发育分析表明，大多数细菌与在其他深海化能合成环境中发现的已知硫化物氧化内共生体有关，Bathymodiolus 标本中存在甲烷氧化共生体。本研究证实了加的斯湾存在几种化学合成双壳类动物，并进一步强调了硫和甲烷氧化共生体在 MV 大型底栖生物群落的营养生态中的重要性。
